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Police say Tatiana Deleao, 31, left her one-year-old child in the car with all the windows closed. (Published Tuesday, Jul 24, 2012)

Updated at 10:18 AM EST on Wednesday, Jul 25, 2012

A New Jersey mother left her toddler in a hot car with the windows rolled up for more than half an hour as she shopped inside a mall, unaware the boy had become unresponsive in the heat, authorities said.

Tatiana Deleao, 31, of Kearny, left her 1-year-old son buckled in a car safety seat as she went shopping inside a T.J. Maxx store on Valley Brook Avenue Saturday afternoon, according to police. The temperature outside at the time was 80 degrees.

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A Good Samaritan who helped bring the boy out said it "felt like an oven" inside the vehicle.

Karen Wagner, a dental receptionist from Lyndhurst, said she was in the parking lot of the strip mall when a woman approached her and told her in broken English there was a baby locked inside a car.

Wagner called 911 and flagged down a passing fire truck. Deputy Fire Chief Daniel Rente jumped out and opened the driver's door of the car to find the baby unresponsive.

"He's standing and holding the baby, and the baby was lifeless," Wagner told NBC 4 New York, emotional as she recalled seeing the child. "Nothing. Even when I put my hand on his chest, nothing. He was saturated in sweat."

"One of the officers that showed up, he's opening up his medical bag, and I said, 'Oh my God, hurry up, the baby is dying," said Wagner.

By the time police officers arrived, a crowd had gathered near the car, and when the baby's mother and her sister emerged from the store, a man said he had seen her an hour ago in Radio Shack, said Wagner.

"The police officers took her away, and her sister was screaming, 'Oh my God, you left the baby, you left the baby,'" said Wagner.

The baby was taken to Clara Maas Hospital in Bellevelle, and is expected to be OK.

Deleao allegedly told an officer she forgot that she'd left her son in the car. Attorney information on Deleao was not immediately available.

Deleao was taken into police custody and charged with child endangerment. She was released on $25,000 bond.

Wagner, a mother of three, said it was motherly instinct that helped her spring into action.

"I was in the right place at the right time," she said.

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